This application relates to a method for removal and recovery of an organic amine from a hydrocarbon stream.
In the chemical industry, processes are often conducted resulting in an outlet stream product or a feed stream to a process unit comprising hydrocarbon and amines. An example is the outlet stream from a reactor used for preparing linear alpha-olefins (LAOs) by oligomerization of ethylene. The linear alpha-olefins produced are then separated into different fractions for further use or marketing. Often, an amine is added during the oligomerization process or is added into a reactor outlet piping system. Such processes are, for example, disclosed in U.S. Pat. No. 5,811,619 or WO2009/095147. In other processes amines are used as corrosion inhibitors or for adjustment of a pH value.
In many cases, it is difficult to remove the organic amine from the hydrocarbon stream by distillation, because the boiling points of the amine and the hydrocarbon stream (or fractions thereof) are very close. For example, n-dodecylamine (DDA) is often added to oligomerization processes, which after product fractionation is carried through to the C14-LAO product fraction. Since DDA has a boiling point close to the C14-LAO product, it cannot readily be removed by distillation.
EP 2 258 674 A1 discloses a method for removal of an organic amine from a hydrocarbon stream comprising the steps of reacting the amine of the hydrocarbon stream containing the amine with an acid, optionally extracting the amine-salt formed into an aqueous phase, and optionally recovering and recycling of the amine. Using this method, the phase separation of organic and aqueous phases is time consuming, which is detrimental for industrial processes.